[DEV-52] Plugins reloaded: Metrics and Diagnostics support

[RagingKore]

Added: new Plugin base class for a simpler implementation with diagnostics and metrics support
Added: new SubsystemsPlugin base class for a simpler implementation with diagnostics and metrics support
Added: PluginDiagnosticsDataCollector to collect all data diags from the plugins
Added: automatic license checking if a licence public key is provided.
Fixed: Licence test
Changed: IPlugableComponent removing CollectTelemetry method and adding other properties like Name and Version
Removed: Serilog dependency

Background and Motivation

Creating plugins should be simpler, and support pushing metrics and diagnostics data to the host.
Connectors are a prime example of a plugin that requires all these capabilities on top of an improved dev ex.

Solution

• Plugin base classes were created with automatic default behaviours and values. The new Plugin base class has the capability to publish diagnostics to the system via DiagnosticsListener.
• There is now automatic license checking if a licence public key is provided.
• This also allowed for the removal of coupled and the weakly typed CollectTelemetry operation.
• The plugin now has a default name based on the implementing class without the suffixes of Plugin, Component and Subsystem and Subsystems
• PluginDiagnosticsDataCollector component to be used in ESDB in order to replace the TelemetryService logic.

public class TcpApiPlugin() : SubsystemsPlugin(licensePublicKey: LicensePublicKey) {
    const string LicensePublicKey = "ZKfMEgCQQDGtRXI-bla-bla-blagkAPOZHTbPQM5AgMBAAE=";

    protected override (bool Enabled, string EnableInstructions) IsEnabled(IConfiguration configuration) {
        var options = configuration.GetSection("EventStore").Get<EventStoreOptions>() ?? new();

        return options.TcpPlugin.EnableExternalTcp
            ? (true, "")
            : (false, "To enable set EnableExternalTcp plugin setting to true");
    }

    protected override void ConfigureServices(IServiceCollection services, IConfiguration configuration) =>
        services.AddHostedService<PublicTcpApiService>();
}

public sealed class ConnectorsPlugin : SubsystemsPlugin {
    protected override void ConfigureServices(IServiceCollection services, IConfiguration configuration) {
        services.AddSingleton<SystemConnectorsFactory>();
        
        services
            .AddGrpc()
            .AddJsonTranscoding();
        
        services.AddConnectorsControlPlane();
    }

    protected override void ConfigureApplication(IApplicationBuilder app, IConfiguration configuration) =>
        app.UseConnectorsManagement();
}

Bonus

• Removed dependency on Serilog as we can simply use the system ILogger if needed.
• Restructured the solution by moving the .sln file to root and moving tests to test folder.
• Upgraded all packages.
• Refactored the remaining code.